Assessment of ground deformation and seismicity in two areas of intense hydrocarbon production in the Argentinian Patagonia

Abstract

The exploitation of both conventional and unconventional hydrocarbons may lead to still not well-known environmental consequences such as ground deformation and induced/triggered seismicity. Identifying and characterizing these effects is fundamental for prevention or mitigation purposes, especially when they impact populated areas. Two case studies of such effects on hydrocarbon-producing basins in Argentina, the Neuquén and the Golfo de San Jorge, are presented in this work. The intense hydrocarbon production activities in recent years and their potential link with the occurrence of two earthquakes of magnitude 4.9 and 5 near the operating well fields is assessed. A joint analysis of satellite radar interferometry and records of fluid injection and extraction demonstrate that, between 2017 and 2020, vertical ground displacements occurred in both study areas over active well fields that might indicate a correlation to hydrocarbon production activities. Coseismic deformation models of the two earthquakes constrain source depths to less than 2 km. The absence of seismicity before the beginning of the hydrocarbon activities in both areas, and the occurrence of the two largest and shallow earthquakes in the vicinity of the active well fields just after intensive production periods, points towards the potential association between both phenomena.

La explotación de hidrocarburos no convencionales en la provincia de Neuquén: Cambios y transformaciones en la localidad de Añelo

“…Con el pasar de los años, han aumentado también las denuncias de habitantes y advertencias de sectores científicos respecto a la relación entre la actividad sísmica y el fracking, fenómeno asociado especialmente a la inyección de agua y aditivos. El aumento de la presión de la roca o la introducción de los fluidos en la misma, pueden producir movimientos en la tierra (Tamburini-Beliveau et al, 2022). En Estados Unidos, algunos estudios han alertado sobre esta problemática desde hace una década, siendo el caso más resonante el de Oklahoma, donde se ha experimentado un aumento de los temblores desde que inició la explotación, debido, sobre todo, al depósito de las aguas de desecho de la actividad en pozos viejos (United States Geological Suvery [USGS], s/f).…”